Sodium percarbonate and sodium perborate are currently used primarily as bleaching base agents in bleaching agents and bleaching detergents. However, because only insufficient bleaching performance is obtained by only these base agents, bleaching activators such as TAED (tetraacetylethylenediamine) and AOBS (sodium alkanoyloxybenzenesulfonate) have come to be used together. These bleaching activators react with hydrogen peroxide generated from peroxides such as sodium percarbonate to generate an organic peracid having high bleachability, producing an effect on bleaching of clothes. The bleaching activator is mixed with a surfactant, a binder and the like and the mixture is then granulated and then the granule is formulated and used in detergents for clothes depending on the situation. It is so devised that such bleaching activator granules are improved in solubility as described in, for example, JP-B5-440.